Printing machine incorporating spacedfont print roll, and method of printing



April 11, 1967 R -n55 3,313,390

PRINTING MACHINE INCORPORATING SPAGED-FONT PRINT ROLL, AND METHOD OF PRINTING Filed Jan 18, 1965 a vcnwooa vwomvmu R m w m R BY ROBE T H CURTISS imam 9 ,&W

I ATTORNEYS United States Patent 3 313 390 PRINTING MAtIHINEdNORPORATING SPACED- FDNT PRINT ROLL, AND METHGD 0F PRDJT- ENG Robert H. Curtiss, Wayland, Mass, assignor to Anelex Corporation, Boston, Mass., a corporation of Massachusetts Filed Jan. 18, 1965, Ser. No. 426,034 6 Claims. (Cl. 197-433) This invention relates to a printing machine incorporating an improved print roll having spaced fonts, as well as to an improved method of printing by means of such a print roll. The invention particularly relates to the type of high-speed printer which has a cylindrical print roll bearing a series of circumferentially-extending type fonts upon the roll surface, one font being conventionally provided for each vertical column of characters to be printed. The paper which is to be printed is fed tangentially to the roll, and each of a plurality of hammers cooperates with one of the type fonts. Means for sensing the angular position of the roll serve to compare the characters passing through a printing station with pre-registered printing information, and to actuate the hammers to impact the paper against a selected character as that character passes through the printing station. In this way, a full line of print is completed during a single uninterrupted revolution of the print roll; the paper is then advanced by a feeding mechanism for the printing of a succeeding line.

This mechanism suffers several disadvantages from the required close spacing of the characters in each line; a typical character width may be .1 inch. As it is necessary to provide an individual hammer for each column, highly compact but rugged hammer mechanisms have had to be devised, and these are relatively expensive to manufacture and to maintain in good working order.

Another disadvantage arising from the close-packed spacing of the characters is a tendency to produce ghost impressions of characters adjacent to the character being printed. If the paper has any substantial stiffness, the impact of a hammer required to imprint the selected character tends to press the paper in the adjoining column spa es against their corresponding fonts with sufiicient force to produce a smudge or partial impression.

It is the primary object of the present invention to provide an improved print roll and an improved printing machine incorporating this print roll, which are of reduced complexity but at the same time produce printing of improved quality and clarity. It is a further object to provide an improved method for producing impressions by means of print roll. Further objects and advantages of the invention will become apparent as the following description proceeds.

Briefly stated, I may carry out my improved method by first preparing a print roll with a series of circumferential type fonts, and spacing the type fonts apart axially on the roll surface with a separation of one of more character widths, so that an intervening series of spaces are blank. These blank areas are preferably of a reduced diameter to avoid contact with the paper. In this way, the impaction of the paper against the type does not cause any adjacent areas of the paper to contact any portion of the roll, and multiple ghost impressions are avoided.

I then rotate the print roll in tangential relation to a length of paper which it is desired to imprint, and, as a desired character passes through a printing station confronting the paper, I impact the paper against the print roll. This operation completes only a portion of a line of print, as it imprints characters only in those columns 3,313,390 Patented Apr. 11, 1967 which confront the spaced-apart fonts. I then shift the paper relative to the print roll, in the direction of the line of print, a distance suflicient to position a group of previously-unprinted columns in opposition to the type fonts, and repeat the printing and shifting steps until the full line is completed. As each line is completed, the paper is fed forwardly into position for printing a succeeding line.

In an embodiment of the invention in a printing machine suitable for performing this process, I prefer to mount paper-feeding tractors for reciprocating movement in the direction of the line of print, either by affixing them to a paper-feed shaft which is slidably and rotatably mounted, or by mounting the tractors slidably upon a drive shaft which is rotatable. Alternatively, the print roll and hammer mechanisms may be reciprocated by mounting them in a common reciprocable carriage, as it is only necessary to bring about a relative shifting movement between the print roll and paper.

In the preferred form of mechanism, reciprocation is effected by means of a pair of opposed solenoids acting upon a common armature, which has pivotal driving connection with the paper-feed shaft, or directly with the tractors. For advancing the paper length-wise the tractors are driven rotatably by conventional means such as a pulley, which may have a sliding connection with the paper-feed shaft if the shaft itself is to be reciprocable. The print roll is rotatably mounted in a stationary locus, and a number of hammer mechanisms are mounted in positions to impact the spaced type fonts at a printing station where the paper passes in tangential relation to the print roll.

While the improved method and mechanism requires a plurality of rotations of the print roll to complete a single line of printing, and consequently prints at a fundamentally lower rate than a conventional roll printer, the smaller number of hammer mechanisms, the increased lateral spacing between them, and the reduced number of type fonts required, greatly reduce the complexity and cost of the mechanism and facilitate maintenance, as well as providing an improved quality of printing by overcoming the problem of multiple ghost impressions by adjacent type fonts.

While the specification concludes with claims particularly pointing out the subject matter which I regard as my invention, it is believed that a clearer understanding may be gained from the following detailed description of a preferred embodiment and pratcice thereof, referring to the accompanying drawings, in which:

FIG. 1 is a schematic view showing the relationship between elements of a preferred embodiment of the invention in a printing machine; and

FIG. 2 is a fragmentary view in front elevation.

Referring to the drawing, the improved printing machine incorporates a print roll 10 having a series of circumferential type fonts 12, which are spaced apart axially of the roll by intervening blank areas 14. In the embodiment shown, the widths of the blank areas and fonts are each equal to a single column of print, so that a full line is printed during two rotations of the print roll and one intermediate relative shifting of the paper 16. However, the width of the areas 14 may be any desired multiple of the column width; a corresponding number of repetitions of the printing and shifting operations would be required. Preferably, the diameter of the blank areas is somewhat less than that of the type fonts, in order to reduce to a minimum the opportunity for the paper to receive a ghost impression by impacting any surface other than that of the type characters being printed. The roll may be prepared by turning or grinding processes, followed by etching of the type fonts, or in any other conventional manner.

The print roll is rotated at a constant speed by suitable motive means (not shown) through a belt 17 and pulley 18, and is rotatably mounted in frame members 20, 22 upon a shaft 24. Sensing of the rotary position of the roll is attained in a conventional manner by affixing a code wheel 26 on the shaft, and mounting sensing elements in a frame member 28 for detecting the roll position and transmitting this information to suitable control apparatus (not shown). The sensing element may comprise a lamp 3% and a photoelectric cell 32, for cooperation with holes punched in the code disc to identify each character of the type font by a binary code; however, this apparatus in itself forms no part of the present invention and will not be described in detail.

A series of hammers 34 are mounted in actuating modules 36, each in tangential relation to one of the type fonts 12, and are actuated by the control apparatus upon agreement of pre-registered printing infonnation with the arrival of the desired characters at the printing station. Printing is performed by impressing the paper 16 and an inked ribbon 38 against the print roll. The inked ribbon is carried in tangential relation to the print roll by guides 40, 42.

The paper is fed in intermittent steps to the printing station for the printing of successive lines, by a pair of tractors 44 having pins 46 engageable in mating openings 47 punched in the longitudinal edges of the paper. In the illustrated embodiment, the tractors are fixed on a splined shaft 48 by means of manual clamping devices 50, and the entire shaft is reciprocate-d in the direction of the printed lines for printing of alternate groups of characters. However, the shaft may be permitted to remain axially stationary if the tractors are slidably mounted on the shaft for reciprocation by other means. Furthemore, it should be understood that it is only necessary to produce a relative reciprocation of the tractors with respect to the print roll and hammers; the invention could therefore be carried out alternatively by reciprocating the print roll and hammers as a unit, on a suitable carriage.

The splined paper-feed shaft 48 is supported for axial and rotational movement by means of a ball bushing 52 and a splined pulley 54. The ball bushing is mounted in a frame element 56 and slidably and rotatably receives a shaft bushing 58, while the splined pulley 54 is axially located and rotatably supported in a frame member 58 by bearings 60 mounted in a housing 62.

Intermittent feeding of the paper to print successive lines is performed by driving the pulley 54 through-a belt 64, a jack-shaft 78, a combination clutch and brake 66, and a belt 68 drivingly connected with suitable motive means (not shown). The clutch-brake 66 is preferably of an electro-magnetic type adapted alternatively to drive or to brake the tractors, and is energized through leads 70 by suitable control apparatus (not shown) to advance the paper for printing successive lines according to a predetermined format. The format is established by a pre-punched tape 72, driven by the jack-shaft. Brushes 74 supply format information to the control apparatus. A counting disc 76 is also mounted on the drive shaft 78, for cooperation with an impulse generator 80 to supply the control apparatus with information as to the precise extent of feeding movement of the paper; this information is used to reverse the energization of the clutch-brake 66 for halting the paper in precise position for printing each successive line. The control apparatus is arranged to advance the paper only subsequent to completion of the printing of each line of characters.

Reciprocation of the tractors 44 and the spline shaft 48 is brought about under the direction of the control apparatus by means of a double solenoid actuating device 82, in which coils 83, 84 are alternatively energized to actuate a pivotally-mounte-d armature 86 as shown by the arrow. The alternate terminal positions of the armature are defined by threaded stops 88, for the precise location of the paper in alternate columnar relationship to the print roll. The armature terminates in a pivotal connection at 90 with a recessed portion 92 of the shaft bushing 58.

In operation, assuming that the paper is initially in a position relative to the print roll for the printing of oddnumbered alternate columns, the clutch-brake 66 and the solenoid actuator 82 are energized to hold the paper in this position, as the print roll rotates through a revolution and the hammers 34 are actuated by the control apparatus to imprint selected characters in these columns. The armature 86 is then actuated by a reversal of the previous energization of the coils 83, 84, to shift the splined shaft 48, the tractors and the paper, so as to position the even-numbered alternate columns in confrontation with the type fonts 12. The printing of the remainder of the line is then concluded by a further revolution of the print roll and appropriate actuations of the hammers 34 to print the selected characters in these columns.

At this point, the energization of the clutch-brake 66 is reversed to rotate the splined shaft and tractors to drive the paper forwardly and position it for the printing of a subsequent line. The paper feeding movement is terminated by renewed braking action under the direction of the control tape 72 and counting disc 76. In relation to the print roll, the even-numbered columns of the paper remain opposed to the type fonts; these columns are printed in a first operation of the print roll and hammers, after which the armature 86 is reversed to return the tractor and papers to their original lateral position, for printing the odd-numbered columns in this second line. Thus, the printing of each complete line entails two printing revolutions of the print roll, and one shifting movement of the tractors and paper either to the left or the right, depending upon the location of the paper at the commencement of that printing operation.

It will be apparent to those skilled in the art that various changes and modification may be made in the preferred embodiment of the apparatus which has been described without departing from the true spirit of the invention; and that the improved method of printing may be carried on by other apparatus. For example, the relative lateral shifting movement of the paper with respect to the print roll and hammers may be carried out either by moving the paper tractors, or by moving the print roll and hammers as a unit, with respect to the machine frame. Also, the type fonts may be interspersed with blank areas whose width is any multiple of the column width, although in the form shown the blank areas are of a single column width. However, the number of printing operations required to complete each line depends upon the number of columnar widths between adjacent fonts. I intend to define the invention in the appended claims without limitation to details of the illustrated embodiment and mode of practice of the invention.

What I claim is: 1. The method of printing successive lines of characters upon a length of paper, which comprises the steps of: preparing a cylindrical print roll with a series of circumferential type fonts spaced apart axially on the roll surface by intermediate blank spaces;

continuously rotating said print roll in tangential relation to the surface of the paper while impressing the paper against selected type characters as said characters pass in confronting relation to the paper surface, to imprint spaced-apart characters of a line, in columnar positions confronting said fonts;

shifting the paper relative to said print roll in the direction of the printed line a distance sufiicient to align a group of previously-unprinted columns in confronting relation ot the type fonts;

continuing the rotation of said print roll while impressing the paper against selected type characters to imprint intermediate spaced-apart characters in the line;

and repeating the steps of relatively shifting the paper and impressing it against the type fonts until the line of characters is completely printed.

2. The method of printing successive lines of characters upon a length of paper, which comprises the steps of:

preparing a cylindrical print roll with a series of circumferential type fonts spaced apart axially on the roll surface at intervals of one or more character widths by intermediate blank spaces;

continuously rotating said print roll in tangential relation to the surface of the paper, while impressing the paper against selected type characters as said characters pass in confronting relation to the paper surface, to imprint spaced-apart characters of a line, in columnar positions confronting said fonts;

shifting the paper laterally relative to said print roll in the direction of the printed line a distance equal to one or more character widths to align a group of previously-unprinted spaces in confronting relation to the type fonts;

continuing the rotation of said print roll while impressing the paper against selected type characters to imprint intermediate spaced-apart characters in the line;

repeating the steps of relatively shifting the paper and impressing it against the type fonts until the line of characters is completely printed;

advancing the paper longitudinally to a position for printing a succeeding line while holding the paper in its present lateral position relative to said print roll;

and repeating the steps of rotating, impressing, shifting,

and advancing to print succeeding lines.

3. A printing machine comprising:

tractor means for feeding paper longitudinally in intermittent steps to a printing station for the printing of successive lines and for holding the paper stationary during the printing of each line;

a print roll rotatably mounted on an axis extending parallel to the direction of the lines to be printed, said roll being tangential to the paper at said printing station, and having a plurality of circumferential type fonts spaced apart axially thereof at intervals of one or more character widths by intermediate blank areas on the print roll;

a plurality of movable hammer means each operatively opposed to one of said fonts and correspondingly spaced apart axially of said print roll, each for imprinting selected characters by impressing the paper against a corresponding one of said fonts as a selected character passes said printing station during rotation of said print roll;

and means for reciprocating said tractor means relative to said print roll and hammer means, parallel to the longitudinal direction of the line to be printed, to at least two discreet positions spaced apart by the width of one character space, such that a line is partially imprinted with spaced-apart characters sequentially imprinted during a first rotation of said print roll while said tractor means remain in a first of said discreet positions, and the imprinting of the line is completed by movement of said tractor means parallel to said direction to another of said discreet positions and by subsequent sequential imprinting of intermediate spaced-apart characters during further rotation of said print wheel.

4. A printing machine as recited in claim 3, together with a paper-feed shaft, said tractor means being affixed to said shaft, said shaft being intermittently rotatable for feeding paper to said printing station for printing of successive lines and being axially reciprocable for shifting said tractor means between said discreet positions; and motive means for rotationally driving said shaft and said tractors, said motive means having a rotational driving connection with said shaft constructed and arranged to permit axial reciprocation of said shaft.

5. A printing machine as recited in claim 4, in which said means for reciprocating said tractor means comprises a reversible electro-magnetic actuator including a pivotally-supported armature having pivotal driving connection with said shaft for reversible axial displacement thereof.

6. A printing machine as recited in claim 3, in which the diameter of said print roll is reduced at said blank areas relative to its diameter at said type fonts, to prevent incidental impression of said paper against said print roll except in areas directly impacted by said hammer means against said type fonts.

References Cited by the Examiner UNITED STATES PATENTS 2,080,649 5/1937 Breitling 101-96 2,746,304 5/1956 Kuhlmann 197-176 2,776,618 1/1957 Hartley 101-93 2,815,843 12/1957 Bellinger et al. 197-20 2,851,267 9/1958 Davidson 197-177 2,897,940 8/1959 Higgonnet et al. 19712 3,091,387 5/1963 Locke 197-196 3,128,693 4/1964 Thiemann 101-93 3,157,115 11/1964 West et al. 101-93 3,167,002 1/1965 Kanada et al. 101-93 3,169,473 2/1965 Irwin et al. 101-93 3,207,067 9/1965 Schaller 101-93 WILLIAM B. PENN, Primary Examiner. 

1. THE METHOD OF PRINTING SUCCESSIVE LINES OF CHARACTERS UPON A LENGTH OF PAPER, WHICH COMPRISES THE STEPS OF: PREPARING A CYLINDRICAL PRINT ROLL WITH A SERIES OF CIRCUMFERENTIAL TYPE FONTS SPACED APART AXIALLY ON THE ROLL SURFACE BY INTERMEDIATE BLANK SPACES; CONTINUOUSLY ROTATING SAID PRINT ROLL IN TANGENTIAL RELATION TO THE SURFACE OF THE PAPER WHILE IMPRESSING THE PAPER AGAINST SELECTED TYPE CHARACTERS AS SAID CHARACTERS PASS IN CONFRONTING RELATION TO THE PAPER SURFACE, TO IMPRINT SPACED-APART CHARACTERS OF A LINE, IN COLUMNAR POSITIONS CONFRONTING SAID FONTS; SHIFTING THE PAPER RELATIVE TO SAID PRINT ROLL IN THE DIRECTION OF THE PRINTED LINE A DISTANCE SUFFICIENT TO ALIGN A GROUP OF PREVIOUSLY-UNPRINTED COLUMNS IN CONFRONTING RELATION TO THE TYPE FONTS; CONTINUING THE ROTATION OF SAID PRINT ROLL WHILE IMPRESSING THE PAPER AGAINST SELECTED TYPE CHARACTERS TO IMPRINT INTERMEDIATE SPACED-APART CHARACTERS IN THE LINE; AND REPEATING THE STEPS OF RELATIVELY SHIFTING THE PAPER AND IMPRESSING IT AGAINST THE TYPE FONTS UNTIL THE LINE OF CHARACTERS IS COMPLETELY PRINTED. 